I’ve put some more effort into my uWSGI + cffi + pypy + ASGI + trio plugin at https://github.com/dholth/uwsgi . The cffi embedding interface lets us write a single plugin that can be recompiled to also work (more slowly) with CPython. The highlight of this version is an incredibly easy to try container at https://github.com/dholth/uwsgi-pypy-demo
ASGI is a WSGI-inspired interface for asynchronous web applications. The inscrutable magic of greenlets lets the server host ASGI and WSGI applications at the same time. uWSGI also handles websockets.
uWSGI is great because it takes care of process management as well as running your application, and it is very resource efficient. I point it at a directory full of config files to keep many services running.
Let me know if you give it a try. Do people still use uWSGI?